Introduce a helper function to program the ISA DMA controller. Program
the ISA DMA as described in Documentation/DMA-ISA-LPC.txt.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/das1800.c | 48 ++++++++++++++------------------
1 file changed, 21 insertions(+), 27 deletions(-)
diff --git a/drivers/staging/comedi/drivers/das1800.c b/drivers/staging/comedi/drivers/das1800.c
index c8ad7dd..6df58cd 100644
--- a/drivers/staging/comedi/drivers/das1800.c
+++ b/drivers/staging/comedi/drivers/das1800.c
@@ -452,6 +452,19 @@ static const struct comedi_lrange range_ao_2 = {
};
*/
+static void das1800_isadma_program(struct das1800_dma_desc *dma)
+{
+ unsigned long flags;
+
+ flags = claim_dma_lock();
+ clear_dma_ff(dma->chan);
+ set_dma_mode(dma->chan, DMA_MODE_READ);
+ set_dma_addr(dma->chan, dma->hw_addr);
+ set_dma_count(dma->chan, dma->size);
+ enable_dma(dma->chan);
+ release_dma_lock(flags);
+}
+
static inline uint16_t munge_bipolar_sample(const struct comedi_device *dev,
uint16_t sample)
{
@@ -571,12 +584,11 @@ static void das1800_handle_dma(struct comedi_device *dev,
flags = claim_dma_lock();
das1800_flush_dma_channel(dev, s, dma);
- /* re-enable dma channel */
- set_dma_addr(dma->chan, dma->hw_addr);
- set_dma_count(dma->chan, dma->size);
- enable_dma(dma->chan);
release_dma_lock(flags);
+ /* re-enable dma channel */
+ das1800_isadma_program(dma);
+
if (status & DMATC) {
/* clear DMATC interrupt bit */
outb(CLEAR_INTR_MASK & ~DMATC, dev->iobase + DAS1800_STATUS);
@@ -998,8 +1010,6 @@ static void setup_dma(struct comedi_device *dev, const struct comedi_cmd *cmd)
{
struct das1800_private *devpriv = dev->private;
struct das1800_dma_desc *dma = &devpriv->dma_desc[0];
- unsigned long lock_flags;
- const int dual_dma = devpriv->irq_dma_bits & DMA_DUAL;
unsigned int bytes;
if ((devpriv->irq_dma_bits & DMA_ENABLED) == 0)
@@ -1011,29 +1021,14 @@ static void setup_dma(struct comedi_device *dev, const struct comedi_cmd *cmd)
bytes = suggest_transfer_size(cmd);
dma->size = bytes;
- lock_flags = claim_dma_lock();
- disable_dma(dma->chan);
- /* clear flip-flop to make sure 2-byte registers for
- * count and address get set correctly */
- clear_dma_ff(dma->chan);
- set_dma_addr(dma->chan, dma->hw_addr);
- /* set appropriate size of transfer */
- set_dma_count(dma->chan, dma->size);
- enable_dma(dma->chan);
- /* set up dual dma if appropriate */
- if (dual_dma) {
+ das1800_isadma_program(dma);
+
+ /* set up dual dma if appropriate */
+ if (devpriv->irq_dma_bits & DMA_DUAL) {
dma = &devpriv->dma_desc[1];
dma->size = bytes;
- disable_dma(dma->chan);
- /* clear flip-flop to make sure 2-byte registers for
- * count and address get set correctly */
- clear_dma_ff(dma->chan);
- set_dma_addr(dma->chan, dma->hw_addr);
- /* set appropriate size of transfer */
- set_dma_count(dma->chan, dma->size);
- enable_dma(dma->chan);
+ das1800_isadma_program(dma);
}
- release_dma_lock(lock_flags);
}
/* programs channel/gain list into card */
@@ -1299,7 +1294,6 @@ static int das1800_init_dma(struct comedi_device *dev,
flags = claim_dma_lock();
disable_dma(dma->chan);
- set_dma_mode(dma->chan, DMA_MODE_READ);
release_dma_lock(flags);
}
--
2.0.3
_______________________________________________
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxx
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
